ABSTRACT This proposal is to request support for a Keystone Symposia meeting entitled [unreadable]Chemokines and Chemokine Receptors[unreadable], which will be held in Keystone, Colorado from January 13 [unreadable] 18, 2008. Cell migration is a key element for the ontogenesis of lymphoid tissues under homeostatic and pathological conditions, for the patrolling of body compartments by leukocytes, and for the activation and orientation of innate and adaptive immunity. Chemokines are a major component of the trafficking, positioning and functional regulation of leukocytes and nonhematopoietic cells in normal conditions and in diverse pathologies. Structural analysis and imaging approaches have resulted in a better understanding of the action of this complex family of mediators. Chemokines are a prime target for the development of innovative therapeutic strategies, some of which are beginning to undergo clinical assessment. This meeting will bring together scientists and clinicians with different expertise to summarize the current understanding of the chemokine system and its involvement in human pathology, focusing on prospects and challenges for translation into new diagnostic and therapeutic tools.